utils.dart

class Utils {
  static bool isNullOrEmpty(String s) {
    return s == null || s == '';
  }

  static String stripTags(String s) {
    return s.replaceAll(new RegExp('<[^>]*>'), '');
  }

  static Set<String> urlMatchs(String s) {
    RegExp exp = new RegExp(
        r"https?:\/\/(www\.)?[-a-zA-Z0-9@:%._\+~#=]{2,256}\.[a-z]{2,6}\b([-a-zA-Z0-9@:%_\+.~#?&//=]*)");

    return exp.allMatches(s).map((m) => m.group(0)).toSet();
  }
}